(1) Field of the Invention
The technical field relates to a method for fabricating a chip having a water-repellent obverse surface and a hydrophilic reverse surface.
(2) Description of Related Art
U.S. Pat. No. 7,730,610 discloses a method for disposing small components 20 such as chips on a substrate 10. This method is referred to as “FSA method”. In the FSA method, as shown in FIG. 15A, prepared is the substrate 10 including a plurality of hydrophilic regions 11 and a water-repellent range 12 which surrounds the plurality of the hydrophilic regions 11. Then, as shown in FIG. 15B, the components 20 to be disposed on the substrate are dispersed in a solvent 40 which is substantially insoluble in water, so as to prepare a component-dispersing liquid 50. Since the reverse surface of the component 20 is hydrophilic, the reverse surface of the component 20 is able to be in contact with one of the hydrophilic regions 11. On the contrary, the obverse surface is water-repellent. Not only the obverse surface but also surfaces other than the reverse surface of the component 20 are water-repellent.
Then, as shown in FIG. 15C, water is disposed on the plurality of the hydrophilic regions 11 with a first squeegee 61. Subsequently, the component-dispersing liquid 50 is applied with a second squeegee 62 to bring the component-dispersing liquid 50 into contact with the water 31 which has been disposed on the hydrophilic regions 11. In this procedure, each component 20 moves into the water 31 which has been disposed on the hydrophilic region 11. At this stage, the hydrophilic reverse surface faces the hydrophilic region 11. Subsequently, the water 31 and the solvent contained in the component-dispersing liquid 50 are removed so as to dispose the component 20 on the hydrophilic region 11. The reverse surface of the disposed component 20 is in contact with the hydrophilic region 11. U.S. Pat. No. 7,730,610 is incorporated herein by reference.